media: Remove VaapiVP8Encoder media_feature

VP8 HW encoding on intel platform is enabled by default from M72.
It has been tested for sufficient time. Now, the media-feature for VP8 HW
encoding becomes unnecessary.

Bug: 794608
Test: None
Change-Id: I18d2537f5ed374a6affcab29c03a1f1c61268c2e
Reviewed-on: https://chromium-review.googlesource.com/c/1462376
Reviewed-by: Becca Hughes <beccahughes@chromium.org>
Reviewed-by: Pawel Osciak <posciak@chromium.org>
Reviewed-by: Hirokazu Honda <hiroh@chromium.org>
Commit-Queue: Hirokazu Honda <hiroh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#631117}
3 files changed